This invention relates to a means for changing carburetor jets of high performance automobile carburetors such as those which have been manufactured for many years by the Holley Carburetor Division of Colt Industries, Warren Michigan. Such carburetors include a metering block attached to the side or sides of the carburetor and a float bowl attached to the side of the metering block. Jets threaded into the metering block, on the float bowl side, control the flow of gasoline into the carburetor. When changes in temperature, humidity, air density or driving style (such as from road use to racing use) occur, the jets must be changed for optimum performance. Unfortunately, changing the jets requires draining the float bowls, and then removing the float bowl and float assembly. The job is difficult, time-consuming and hazardous, and quickly wears out the gasket between the metering block and float bowl.